mm/damon/core: support damos_filter->allow

mm/damon/core: support damos_filter->allow

DAMOS filters supports allowing behavior, but the core layer's DAMOS
filters handling logic still assumes only rejecting (filtering-out)
behavior.  Update the logic to aware of and respect the behavioral
decision by reading damos_filter->allow when making the decision to
exclude a region or not.

Link: https://lkml.kernel.org/r/20250109175126.57878-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>